Lanthanide terbium complex: synthesis, electrochemiluminescence (ECL) performance, and sensing application.

In this study, a new lanthanide terbium complex, Tb(pzda)3(NO3)3·nH2O, was synthesized by a hydrothermal method and characterized by Fourier transform infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDS). It was found that the as-synthesized Tb-complex exhibited good electrochemiluminescence (ECL) behavior in the presence of triethanolamine (TEOA) in a HAc-NaAc buffer solution on a glassy carbon electrode. The possible reaction mechanism has been discussed based on the fluorescence spectra and ECL spectra. For sensing applications, it was found that protocatechuic acid (PCA) had an obvious quenching effect on the ECL signal of the Tb-complex, and this resulted in a decreased ECL signal associated with the concentration of PCA. Therefore, a highly sensitive method for the detection of PCA was established with a linear range of 1.283 × 10-10 M to 3.845 × 10-4 M and a detection limit of 0.085 nM at an S/N ratio of 3. This novel ECL assay strategy with an outstanding ECL efficiency offers great potential for pharmaceutical analyses.

Determination of bergenin based on the electrochemiluminescence quenching of tris(2,2'-bipyridine)-ruthenium(II).

Quenching effects of bergenin, based on the electrochemiluminescence (ECL) of the tris(2,2'-bipyridyl)-ruthenium(II) (Ru(bpy)3(2+))/tri-n-propylamine (TPrA) system in aqueous solution, is been described. The quenching behavior can be observed with a 100-fold excess of bergenin over Ru(bpy)3(2+). In the presence of 0.1 m TPrA, the Stern-Volmer constant (KSV ) of the ECL quenching is as high as 1.16 × 10(4) M(-1) for bergenin. The logarithmic plot of the inhibited ECL versus logarithmic plot of the concentration of bergenin was linear over the range 3.0 × 10(-6)-1.0 × 10(-4) mol/L. The corresponding limit of detection was 6.0 × 10(-7) mol/L for bergenin (S/N = 3). In the mechanism of quenching it is believed that the competition of the active free radicals between Ru(bpy)3(2+)/TPrA and bergenin was the key factor for the ECL inhibition of the system. Photoluminescence, cyclic voltammetry, coupled with bulk electrolysis, supports the supposition mechanism of the Ru(bpy)3(2+)/TPrA-bergenin system.

Determination of p-aminobenzenesulfonic acid based on the electrochemiluminescence quenching of tris (2,2'-bipyridine)-ruthenium (II).

This study describes the quenching effects of p-aminobenzenesulfonic acid (p-ABSA) based on electrochemiluminescence (ECL) of the tris (2,2(') -bipyridyl)-ruthenium(II)(Ru(bpy)3 (2+))/tri-n-propylamine (TPrA) system in aqueous solution. Quenching behaviours were observed with a 200-fold excess of p-ABSA over Ru(bpy)3 (2+). In the presence of 0.1 M TPrA, the Stern-Volmer constant (KSV) of ECL quenching was as high as 1.39 × 10(4) M(-1) for p-ABSA. The logarithmic plot of inhibited ECL versus concentration of p-ABSA was linear over the range of 6.0 × 10(-6) -3.0 × 10(-4) mol/L. The corresponding limit of detection was 1.2 × 10(-6) mol/L for p-ABSA (S/N = 3). The mechanism of quenching is believed to involve an energy transfer from the excited-state luminophore to a dimer of p-ABSA and the adsorption of free radicals of p-ABSA at the electrode surface that impeded the oxidation of the Ru(bpy)3 (2+) /TPrA system.

Quenching of the electrochemiluminescence of tris(2,2'-bipyridine)-ruthenium(II) by sodium diphenylamine-4-sulfonate.

Efficient quenching electrochemiluminescence (ECL) of the tris(2,2'-bipyridine)ruthenium(II)/tripropylamine (Ru(bpy)(3)(2+)/TPrA) system by a novel quencher, sodium diphenylamine-4-sulfonate (SDS), has been investigated. The quenching behaviors can be observed with a 100-fold excess of SDS over Ru(bpy)(3)(2+). The mechanism of quenching is believed to involve energy transfer from the excited-state Ru(bpy)(3)(2+*) to the dimer of SDS, which was formed after the electrochemical oxidation of SDS at the electrode surface. Photoluminescence experiments coupled with bulk electrolysis support formation of the SDS dimer upon electrochemical oxidation.